Colouring-matters of the so-called Bile of Invertebrates, fyc. 395 



The chloroform solution gave three bands : — 



1st Band X612— 592 Centre 604 



2nd „ X576— 552 „ 564 



3rd „ \511— 488 „ 499 



The ethereal solution also gave three bands : — 



1st Band , . \610— 589 Centre , 600 



2nd „ ........ A576— 545 „ 562 



3rd „ \509— 488 „ ' 498 



An absolute alcohol solution gave : — 



1st Band X610— 587 *5 Centre 600 



2nd „ \576— 558 „ 567? 



3rd „ X516— 488 „ 502 



This with caustic soda gave two bands : the first from X583 — 561, 

 and second, A521 — 507. 



In a deep layer of an aqueous solution a faint shadow could be 

 seen covering D ; by treatment of this aqueous solution with perman- 

 ganate of potassium, this shadow could be made to disappear ; that at 

 F was narrowed, became hazy, and finally disappeared. So that just 

 as normal urobilin can be reduced back to febrile urobilin, as I formerly 

 showed, so can febrile be oxidised into normal urobilin. 



By acting on an alcoholic solution with caustic soda no bands at C and 

 D in the position of those obtained in a similar solution of hydrobilirubin 

 artificially prepared, or in a similar solution of stercobilin, could be seen. 

 Hence febrile urobilin is not identical, as previously stated (supra), 

 with hydrobilirubin or with stercobilin. If it is derived from sterco- 

 bilin, it has undergone some change before its excretion in the urine. 



Dr. Harley's Urohcematin. — I have repeated Dr. Harley's experi- 

 ments on " urohsematin "* and find not only is his pigment totally 

 different from any that I have described, but a mixture of several 

 decomposition products of chromogens, produced by the action of heat 

 and mineral acids on them ; nor by following out his directions could 

 anything approaching a pure residue be obtained. Hoppe-Seyler's 

 conclusion that his results are only of historical value may therefore 

 be accepted. I mention this, as I had omitted in former papers to say 

 that Dr. Harley had inferred, long before the spectroscope was used in 

 such investigations, that the colouring-matter of urine was derived 

 from that of blood, but the resemblance between his " uroheematin" 

 and the pigments which I have described lies only in the name. 



* " Ueber Urohsematin und seine Yerbindung mit Animalschem Harze." " Aus 

 den Yerhand. der Physicalisch-Med. G-esellsch. zu Wurzburg," Bd. 5, 1854. Also 

 " Pharmac. Journal and Trans," vol. xii, 1852-53, p. 243. 



